Augmented or mixed reality is a technology that allows virtual imagery to be mixed with a user's actual view of the real world. A see-through, near-eye display may be worn by a user to view the mixed imagery of virtual and real objects. The display displays virtual imagery in the user's field of view.
However, the wearer's eyes need to be protected from too much light from the display. The brightness of the display is a combination of how much external light gets through the display and how much light is being used to display images. Thus, if too much external light shines through the display the user may experience eye damage or discomfort. Also, if too much light is used to display images, the user may suffer eye discomfort or damage. Further, the user's eyes need to be protected while still allowing the user to properly see the virtual and real objects properly.